%0 Journal Article
%A Naeem, Karattu
Chali
%A Neenu, Kadaikkara
%A Nair, Vijayakumar C.
%D 2017
%T Effect of Differential Self-Assembly on Mechanochromic
Luminescence of Fluorene-Benzothiadiazole-Based Fluorophores
%U https://acs.figshare.com/articles/journal_contribution/Effect_of_Differential_Self-Assembly_on_Mechanochromic_Luminescence_of_Fluorene-Benzothiadiazole-Based_Fluorophores/5715889
%R 10.1021/acsomega.7b01339.s001
%2 https://acs.figshare.com/ndownloader/files/10035553
%K Fluorene-Benzothiadiazole-Based Fluorophores Supramolecular self-assembly
%K mechanoresponsive luminescence
%K Differential Self-Assembly
%K fluorene-benzothiadiazole-based fluorophores
%K Differential self-assembly
%K nonpolar solvents
%K UV
%K self-assembled state
%K molecules self-assemble
%K FB-C 6
%K alkyl chain length
%K fluorescence spectroscopy
%K scanning electron microscopy
%K Mechanochromic Luminescence
%K X-ray diffraction spectroscopy
%K fluorene moiety
%K time-correlated single-photon
%K FB-C 12
%K alkyl chains
%K donor
%K excitation energy migration properties
%K mechanochromic luminescence properties
%K hydrogen-bonding amide groups
%X Supramolecular self-assembly is an
excellent tool for controlling
the optical and electronic properties of chromophore-based molecular
systems. Herein, we demonstrate how differential self-assembly affects
mechanoresponsive luminescence of fluorene-benzothiadiazole-based
fluorophores. We have synthesized two donor–acceptor–donor-type
conjugated oligomers consisting of fluorene as the donor and benzothiadiazole
as the acceptor. For facile self-assembly, both molecules are end-functionalized
with hydrogen-bonding amide groups. Differential self-assembly was
induced by attaching alkyl chains of different lengths onto the fluorene
moiety: hexyl (FB-C6) and dodecyl (FB-C12). The molecules self-assemble to form well-defined nanostructures
in nonpolar solvents and solvent mixtures. Although their optical
properties in solution are not affected by the alkyl chain length,
significant effects were observed in the self-assembled state, particularly
in the excitation energy migration properties. As a result, remarkable
differences were observed in the mechanochromic luminescence properties
of the molecules. A precise structure–property correlation
is made using UV–visible absorption and fluorescence spectroscopy,
time-correlated single-photon counting analysis, scanning electron
microscopy, and X-ray diffraction spectroscopy.
%I ACS Publications